[Xen-users] Open source drivers with secondary VGA pass through

[Daniel Shub <Daniel.Shub@xxxxxxxxxxxxxxxx>]

I am trying to use the open source Radeon driver on Linux with a passed through 
secondary VGA device. I am running Xen 4.4.0 on Arch Linux (kernel 3.14.6). I 
have Gigabyte X79-UP4 motherboard and two Gigabyte GV-R545-1GI (Radeon 5450 
chipset) video cards. I can pass either (the primary one that the Dom0 BIOS 
comes up on or the secondary one) VGA device to a Windows XP DomU 
(qemu-xen-traditional) as a secondary VGA device in conjunction with virtual 
Cirrus VGA device. The passed device works perfectly and is stable across DomU 
reboots. I can also pass either VGA device to an Arch Linux (kernel 3.14.6) 
DomU (qemu-xen-traditional) as a secondary device and the passed device works 
perfectly with the Catalyst closed source drivers, but doesn't work at all with 
the open source Radeon driver. I know I should just be happy that I can pass 
through VGA devices at all, but I keep hoping I will be able to get it to work 
with the open source drivers.

$ dmesg | grep -E '(radeon|drm)'
[    0.436833] [drm] Initialized drm 1.1.0 20060810
[    0.441222] [drm] radeon kernel modesetting enabled.
[    0.442083] [drm] initializing kernel modesetting (CEDAR 0x1002:0x68F9 
0x1458:0x254A).
[    0.442096] [drm] register mmio base: 0xF3000000
[    0.442097] [drm] register mmio size: 131072
[    0.442127] radeon 0000:00:05.0: Expecting atombios for evergreen GPU
[    0.442161] radeon 0000:00:05.0: Fatal error during GPU init
[    0.442187] [drm] radeon: finishing device.
[    0.449566] radeon: probe of 0000:00:05.0 failed with error -22

The errors look essentially the same as 
https://bugzilla.kernel.org/show_bug.cgi?id=57831, where the claim is that the 
VBIOS is not being passed correctly. How can I determine if my issue is that 
Xen/Qemu is not passing the the correct VBIOS? If this is in fact the case, is 
there a way to fix this without having to use the closed source drivers or 
enter the hell that is primary VGA pass trough? Is it worth filing a bug report 
some place? The driver developers closed the bug as invalid even though the 
closed source driver handles the issue gracefully.
This message and any attachment are intended solely for the addressee and may 
contain confidential information. If you have received this message in error, 
please send it back to me, and immediately delete it.   Please do not use, copy 
or disclose the information contained in this message or in any attachment.  
Any views or opinions expressed by the author of this email do not necessarily 
reflect the views of the University of Nottingham.

This message has been checked for viruses but the contents of an attachment
may still contain software viruses which could damage your computer system, you 
are advised to perform your own checks. Email communications with the 
University of Nottingham may be monitored as permitted by UK legislation.





_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxx
http://lists.xen.org/xen-users